Lifetime cumulative number of menstrual cycles and serum sex hormone levels in postmenopausal women

作者：Mariana Chávez‐MacGregor, Carla Henrica van Gils, Yvonne T. van der Schouw, Evelyn M. Monninkhof, Paulus A.H. van Noord, Petra H.M. Peeters · 发表于：Breast Cancer Research and Treatment · 年份：2007 · DOI：10.1007/s10549-007-9574-z · 被引用次数：60 · 研究领域：Menopause: Health Impacts and Treatments、Cancer Risks and Factors、BRCA gene mutations in cancer

OBJECTIVE: Lifetime cumulative number of menstrual cycles is related to breast cancer risk. The aim of this study is to investigate the relation between this index and serum sex hormone levels in postmenopausal women. METHODS: Cross-sectional study including 860 naturally postmenopausal Dutch participants of the European Prospective Investigation into Cancer and Nutrition. Lifetime cumulative number of menstrual cycles was computed using questionnaire data on ages at menarche and menopause, number of pregnancies, breastfeeding, oral contraceptive use (OC) and regularity pattern. Measurements of hormones included estrone (E1), estradiol (E2), andostrenedione, testosterone, sex-hormone binding globulin (SHBG) and dehydroepiandrostenedione sulfate (DHEAS). The relation between the lifetime cumulative number of menstrual cycles and hormone levels was assessed using analysis of covariance. Relations between reproductive characteristics and hormone levels were also studied. Adjustments for characteristics at blood collection included age, years since menopause, BMI, hormone replacement therapy use, OC use, smoking habits, alcohol intake and physical activity were done. RESULTS: Lifetime cumulative number of cycles was related with SHBG; participants in the lowest category had higher SHBG levels. For the separate characteristics, DHEAS and androstenedione increased significantly with increasing age at menarche, while androstenedione and testosterone decreased with increasing age at ...